NEW YORK -- Rafael Nadal won the first two games of the U.S. Open final against Novak Djokovic, but, in a swift reversal of fortune Monday that was a microcosm of their head-to-head history, Djokovic won the next six games.

In the fifth of those games, something in the usually relentless Spaniard seemed to crack. Twice, Djokovic flashed a cheeky drop shot, and twice, Nadal stopped, frozen, and declined to give chase. When Nadal's weary-looking backhand found the net, Djokovic had broken his serve for the third time -- in the set.

Novak Djokovic is the sixth man in the Open era to win three Grand Slams in one season. Stan Honda/Getty Images

A similarly debilitating (yet thrilling) game, the third of the second set, required 22 points and more than 17 minutes. When Djokovic won that one -- following a blown overhead by Nadal -- the winded 24-year-old Serbian shrugged and raised his right index finger aloft.

That was just about right.

Yes, in his first major as the world's top-ranked player, Djokovic emphatically backed it up. He dismissed the defending champion 6-2, 6-4, 6-7 (3), 6-1 in a match that ran 4 hours, 10 minutes.

"The results that I had this year are amazing and definitely that I haven't expected," Djokovic said. "It keeps coming. In the end, the bottom line, the whole point is to win the Grand Slams. These are the most important and valuable tournaments in our sport."

The funny thing? Nadal played some superb tennis; there were a handful of exquisite points worthy of a frame. In a brutally physical battle, Djokovic was simply better. He broke Nadal an amazing 11 times.

After the final forehand winner dove into the court, Djokovic lay on his back behind the baseline, spread-eagled, overcome. Later, he fell to his knees and kissed the blue court.

His two-week haul: a first U.S. Open title, a check for $2.3 million and a sweet silver trophy.

"Six straight losses, for sure, that is painful," Nadal said. "I have a goal, easy goal. Going to be a tough situation. Goal is easy to see.

"When one very good player stays with that confidence and [is] winning so many matches, the season is probably impossible to repeat. Accept that, accept the challenge. And work."

In his on-court interview, Nadal addressed his opponent:

"What you did this year," he told Djokovic, "is probably impossible to repeat."

Indeed, Djokovic finds himself bearing down on one of the finest seasons in tennis history. He is only the sixth man in the 43 years of the Open era to win three Grand Slam singles titles in the same year, and he already has won a record five ATP World Tour Masters 1000 events. His record -- a scalding 64-2 -- already ranks with the best seasons of Roger Federer and Jimmy Connors, and seems to be within reach of John McEnroe's 82-3 mark in 1984.

In the CBS broadcast booth, McEnroe, who would seem to be an authority, went so far as to call it "the greatest ever."

After he finished as runner-up here twice, in 2007 and 2010, the third time was charming karma for Djokovic. The two visits from the ATP trainer in the fourth set for what was described as a strained back were, apparently, much ado about nothing.

Nadal made a terrific run in the third set, but he was spent in the fourth. Watching Rafa miss shots he usually makes, talk to his box in uncharacteristic staccato Spanish bursts and mix it up with the chair umpire was unsettling, to say the least.

Their head-to-head matchup in tennis is an organic, volatile, always-evolving dynamic.

For five years, Nadal had an overwhelming edge over Djokovic, winning 16 of their 23 meetings, including all five finals. The last victory in that run was the 2010 U.S. Open, which Rafa won in four sets. The edge in sets: Rafa won 36 of 56. The physicality of his game was daunting enough for Djokovic, but what made Nadal so overwhelmingly superior was his mental command. He believed he was going to win, and so he did.

And then, it turned on a dime. In 2011, Djokovic now has beaten Nadal all six times they've played, taking an extraordinary 14 of 17 sets -- each victory coming in a final. Certainly, he's pumped up his fitness, better protected his serve and sharpened his already lethal service return, but the greatest area of improvement has been between the ears.

"I guess it just clicked in my head," Djokovic said. "I didn't change my game in any major way. [It's] just that I'm hitting the shots that maybe I didn't hit in the last three years. I'm going for it; I'm more aggressive."

Djokovic's confidence is currently the game's greatest weapon.

To put it in context: Djokovic is utterly dominating the No. 2-ranked player, who dominates the player (Federer) who is considered by many to be the best player in history.

"Roger was having years when he was winning three majors," Djokovic said. "Rafa did as well. You can say this is my year. Where I perform my best tennis. It's going to take quite an effort to repeat half of what I've done."

After the previous loss, at Wimbledon, Nadal seemed genuinely perplexed at the recent turn of events. After defeating Andy Murray here in the semifinals, Nadal acknowledged that the dynamic had shifted.

"I beat him in the past playing my game," he said. "The thing is [I] play my game very well and be strong enough mentally all the time, fight every ball, believe in the victory every moment. That's something that for moments this year I didn't."

Against Djokovic, his resolve was tested again. The first four times he broke Djokovic's serve, the Serb immediately broke back. In a match that close, in which he was extremely fatigued, Rafa said, he needed more free points from his serve.

It was Nadal whose complaints about the schedule ultimately forced the USTA to move the men's final to Monday. In retrospect, it's possible that shift was an advantage for Djokovic, who had played an emotional five-set match with Federer in the semifinals. After looking sluggish in the first few games, Djokovic snapped into the sublime form that has been virtually unbeatable.

Nadal, early on, was tentative, unwilling to pull the trigger and flatten out his forehand into the open court when the opportunity presented itself. The rest of the way, when he had no choice, the ball sometimes flew off his racket.

This was the 29th meeting between these two relatively young champions, and it certainly won't be the last.

"I wish that we have many more tough matches in the upcoming years," Djokovic said.

Of course he did.

They could clash again in the BNP Paribas Masters, the year-end event in London, and, a week later, in the Davis Cup final -- if Serbia and Spain win their semifinal matches next week.

Based on this definitive result, based on the disarming bouts of frustration that leaked out of Nadal as the match progressed, those matches can go only one way.